puppet: Put comments on iptables lines.
puppet: Put comments on iptables lines.

In addition to documenting the rules.v4 and rules.v6 files slightly,
these comments show up in `iptables -L`:

```
root@hostname:~# iptables -L INPUT
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere
LOGDROP    all  --  anywhere             localhost/8
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh /* ssh */
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:3000 /* grafana */
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:9100 /* node_exporter */
LOGDROP    all  --  anywhere             anywhere
```

zulip/zulip,zulip/zulip,kou/zulip,rht/zulip,zulip/zulip,andersk/zulip,zulip/zulip,zulip/zulip,rht/zulip,kou/zulip,kou/zulip,rht/zulip,andersk/zulip,zulip/zulip,kou/zulip,andersk/zulip,rht/zulip,zulip/zulip,andersk/zulip,kou/zulip,andersk/zulip,rht/zulip,kou/zulip,andersk/zulip,rht/zulip,andersk/zulip,rht/zulip,kou/zulip